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I am new to Data warehousing and have set up multiple Dimension Tables and Fact Tables using a STAR schema. I have a question that using STAR schema, can two dimensions be linked together using a primary key/foreign key approach. I have read that two dimensions can only be linked in a FACT table ? Is this correct ?

Kind Regards

Minzkraut
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AndroidDev
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1 Answers1

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Dimensions can reference another dimension. Just being wary of linking them means there is a chance of explosive growth due to Type2 SCD changes. This approach is called an outrigger dimension used when a dimension table is snowflaked. Outriggers are tables or entities that are shared by more than one dimension.

Srini V
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  • a query to get all locations linked to a product would be meaningful, and querying a smaller dimension table compared to a large fact table would be meaningful as well – user1689987 Feb 03 '22 at 07:13
  • Dimensions can reference another dimension as you said. But linking them means there is a chance of explosive growth due to Type2 SCD changes. This is what we call an outrigger dimension which is used when a dimension table is snowflaked. Outriggers are tables or entities that are shared by more than one dimension. I've edited the answer with this comment. – Srini V Feb 28 '22 at 04:50